X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=include%2Fasm-i386%2Fatomic.h;h=de649d3aa2d45d630874634c11f732e5e4819491;hb=987b0145d94eecf292d8b301228356f44611ab7c;hp=4ddce5296a788a2b6442700f4126bb636cd14df9;hpb=f7ed79d23a47594e7834d66a8f14449796d4f3e6;p=linux-2.6.git

diff --git a/include/asm-i386/atomic.h b/include/asm-i386/atomic.h
index 4ddce5296..de649d3aa 100644
--- a/include/asm-i386/atomic.h
+++ b/include/asm-i386/atomic.h
@@ -10,6 +10,12 @@
  * resource counting etc..
  */
 
+#ifdef CONFIG_SMP
+#define LOCK "lock ; "
+#else
+#define LOCK ""
+#endif
+
 /*
  * Make sure gcc doesn't try to be clever and move things around
  * on us. We need to use _exactly_ the address the user gave us,
@@ -46,7 +52,7 @@ typedef struct { volatile int counter; } atomic_t;
 static __inline__ void atomic_add(int i, atomic_t *v)
 {
 	__asm__ __volatile__(
-		LOCK_PREFIX "addl %1,%0"
+		LOCK "addl %1,%0"
 		:"=m" (v->counter)
 		:"ir" (i), "m" (v->counter));
 }
@@ -61,7 +67,7 @@ static __inline__ void atomic_add(int i, atomic_t *v)
 static __inline__ void atomic_sub(int i, atomic_t *v)
 {
 	__asm__ __volatile__(
-		LOCK_PREFIX "subl %1,%0"
+		LOCK "subl %1,%0"
 		:"=m" (v->counter)
 		:"ir" (i), "m" (v->counter));
 }
@@ -80,7 +86,7 @@ static __inline__ int atomic_sub_and_test(int i, atomic_t *v)
 	unsigned char c;
 
 	__asm__ __volatile__(
-		LOCK_PREFIX "subl %2,%0; sete %1"
+		LOCK "subl %2,%0; sete %1"
 		:"=m" (v->counter), "=qm" (c)
 		:"ir" (i), "m" (v->counter) : "memory");
 	return c;
@@ -95,7 +101,7 @@ static __inline__ int atomic_sub_and_test(int i, atomic_t *v)
 static __inline__ void atomic_inc(atomic_t *v)
 {
 	__asm__ __volatile__(
-		LOCK_PREFIX "incl %0"
+		LOCK "incl %0"
 		:"=m" (v->counter)
 		:"m" (v->counter));
 }
@@ -109,7 +115,7 @@ static __inline__ void atomic_inc(atomic_t *v)
 static __inline__ void atomic_dec(atomic_t *v)
 {
 	__asm__ __volatile__(
-		LOCK_PREFIX "decl %0"
+		LOCK "decl %0"
 		:"=m" (v->counter)
 		:"m" (v->counter));
 }
@@ -127,7 +133,7 @@ static __inline__ int atomic_dec_and_test(atomic_t *v)
 	unsigned char c;
 
 	__asm__ __volatile__(
-		LOCK_PREFIX "decl %0; sete %1"
+		LOCK "decl %0; sete %1"
 		:"=m" (v->counter), "=qm" (c)
 		:"m" (v->counter) : "memory");
 	return c != 0;
@@ -146,7 +152,7 @@ static __inline__ int atomic_inc_and_test(atomic_t *v)
 	unsigned char c;
 
 	__asm__ __volatile__(
-		LOCK_PREFIX "incl %0; sete %1"
+		LOCK "incl %0; sete %1"
 		:"=m" (v->counter), "=qm" (c)
 		:"m" (v->counter) : "memory");
 	return c != 0;
@@ -166,7 +172,7 @@ static __inline__ int atomic_add_negative(int i, atomic_t *v)
 	unsigned char c;
 
 	__asm__ __volatile__(
-		LOCK_PREFIX "addl %2,%0; sets %1"
+		LOCK "addl %2,%0; sets %1"
 		:"=m" (v->counter), "=qm" (c)
 		:"ir" (i), "m" (v->counter) : "memory");
 	return c;
@@ -183,24 +189,23 @@ static __inline__ int atomic_add_return(int i, atomic_t *v)
 {
 	int __i;
 #ifdef CONFIG_M386
-	unsigned long flags;
 	if(unlikely(boot_cpu_data.x86==3))
 		goto no_xadd;
 #endif
 	/* Modern 486+ processor */
 	__i = i;
 	__asm__ __volatile__(
-		LOCK_PREFIX "xaddl %0, %1;"
+		LOCK "xaddl %0, %1;"
 		:"=r"(i)
 		:"m"(v->counter), "0"(i));
 	return i + __i;
 
 #ifdef CONFIG_M386
 no_xadd: /* Legacy 386 processor */
-	local_irq_save(flags);
+	local_irq_disable();
 	__i = atomic_read(v);
 	atomic_set(v, i + __i);
-	local_irq_restore(flags);
+	local_irq_enable();
 	return i + __i;
 #endif
 }
@@ -226,14 +231,8 @@ static __inline__ int atomic_sub_return(int i, atomic_t *v)
 ({								\
 	int c, old;						\
 	c = atomic_read(v);					\
-	for (;;) {						\
-		if (unlikely(c == (u)))				\
-			break;					\
-		old = atomic_cmpxchg((v), c, c + (a));		\
-		if (likely(old == c))				\
-			break;					\
+	while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \
 		c = old;					\
-	}							\
 	c != (u);						\
 })
 #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
@@ -243,11 +242,11 @@ static __inline__ int atomic_sub_return(int i, atomic_t *v)
 
 /* These are x86-specific, used by some header files */
 #define atomic_clear_mask(mask, addr) \
-__asm__ __volatile__(LOCK_PREFIX "andl %0,%1" \
+__asm__ __volatile__(LOCK "andl %0,%1" \
 : : "r" (~(mask)),"m" (*addr) : "memory")
 
 #define atomic_set_mask(mask, addr) \
-__asm__ __volatile__(LOCK_PREFIX "orl %0,%1" \
+__asm__ __volatile__(LOCK "orl %0,%1" \
 : : "r" (mask),"m" (*(addr)) : "memory")
 
 /* Atomic operations are already serializing on x86 */